Topography of Los Angeles

Los Angeles is irregularly shaped and covers a total area of 502.7 square miles (1,302 km²), comprising 468.7 square miles (1,214 km²) of land and 34.0 square miles (88 km²) of water. The city extends for 44 miles (71 km) longitudinally and for 29 miles (47 km) latitudinally. The perimeter of the city is 342 miles (550 km).

Los Angeles is both flat and hilly. The highest point in the city is 5,074 ft (1,547 m) Mount Lukens, located at the northeastern end of the San Fernando Valley. The eastern end of the Santa Monica Mountains stretches from Downtown to the Pacific Ocean and separates the Los Angeles Basin from the San Fernando Valley. Other hilly parts of Los Angeles include the Mt. Washington area north of Downtown, eastern parts such as Boyle Heights, the Crenshaw district around the Baldwin Hills, and the San Pedro district.

The Los Angeles River, which is largely seasonal, is the primary drainage channel. It was straightened and lined in 51 miles of concrete by the Army Corps of Engineers to act as a flood control channel. The river begins in the Canoga Park district of the city, flows east from the San Fernando Valley along the north edge of the Santa Monica Mountains, and turns south through the city center, flowing to its mouth in the Port of Long Beach at the Pacific Ocean. The smaller Ballona Creek flows into the Santa Monica Bay at Playa del Rey.

The Los Angeles area is rich in native plant species due in part to a diversity in habitats, including beaches, wetlands, and mountains. The most prevalent botanical environment is coastal sage scrub, which covers the hillsides in combustible chaparral. Native plants include: California poppy, matilija poppy,toyon, Coast Live Oak, and Giant Wildrye. Many of these native species, such as the Los Angeles sunflower, have become so rare as to be considered endangered. Though it is not native to the area, the official tree of Los Angeles is the Coral Tree (Erythrina caffra) and the official flower of Los Angeles is the Bird of Paradise (Strelitzia reginae). Mexican Fan Palms, California Fan Palms, and Canary Island Palms can be seen throughout the Los Angeles area, despite the latter being non-indigenous to Southern California.